Using zope.password

This package provides a password manager mechanism. Password manager is an utility object that can encode and check encoded passwords. Beyond the generic interface, this package also provides eight implementations:

zope.password.password.PlainTextPasswordManager

The most simple and the less secure one. It does not do any password encoding and simply checks password by string equality. It’s useful in tests or as a base class for more secure implementations.

zope.password.password.MD5PasswordManager

A password manager that uses MD5 algorithm to encode passwords. It’s generally weak against dictionary attacks due to a lack of a salt.

zope.password.password.SMD5PasswordManager

A password manager that uses MD5 algorithm, together with a salt to encode passwords. It’s better protected against against dictionary attacks, but the MD5 hashing algorithm is not as strong as the SHA1 algorithm.

zope.password.password.SHA1PasswordManager

A password manager that uses SHA1 algorithm to encode passwords. It has the same weakness as the MD5PasswordManager.

zope.password.password.SSHAPasswordManager

A password manager that is strong against dictionary attacks. It’s basically SHA1-encoding password manager which also incorporates a salt into the password when encoding it.

zope.password.password.CryptPasswordManager

A manager implementing the crypt(3) hashing scheme. Only available if the python crypt module is installed. This is a legacy manager, only present to ensure that zope.password can be used for all schemes defined in RFC 2307 (LDAP).

zope.password.password.MySQLPasswordManager

A manager implementing the digest scheme as implemented in the MySQL PASSWORD function in MySQL versions before 4.1. Note that this method results in a very weak 16-byte hash.

zope.password.password.BCRYPTPasswordManager

A manager implementing the bcrypt hashing scheme. Only available if the bcrypt module is installed. This manager is considered the most secure.

The Crypt, MD5, SMD5, SHA and SSHA password managers are all compatible with RFC 2307 LDAP implementations of the same password encoding schemes.

Note

It is strongly recommended to use the BCRYPTPasswordManager, as it’s the most secure.

The package also provides a script, zpasswd, to generate principal entries in typical site.zcml files.

Password Manager Interfaces

The zope.password.interfaces.IPasswordManager interface defines only two methods:

    def encodePassword(password):
        """Return encoded data for the given password

        Return encoded bytes.
        """
    def checkPassword(encoded_password, password):
        """Does the encoded password match the given password?

        Return True if they match, else False.
        """

An extended interface, zope.password.interfaces.IMatchingPasswordManager, adds one additional method:

    def match(encoded_password):
        """Was the given data was encoded with this manager's scheme?

        Return True when the given data was encoded with the scheme
        implemented by this password manager.
        """

Looking Up Password Managers via a Vocabulary

The zope.password.vocabulary module provides a vocabulary of registered password manager utility names. It is typically registered as an zope.schema.interfaces.IVocabularyFactory utility named “Password Manager Names”.

It’s intended to be used with zope.component and zope.schema, so you need to have them installed and the utility registrations needs to be done properly. The configure.zcml file contained in zope.password does the registrations, as well as in zope.password.testing.setUpPasswordManagers().

Encrypting Passwords with zpasswd

zpasswd is a script to generate principal entries in typical site.zcml files.

You can create a zpasswd script in your buildout by adding a section like this to your buildout.cfg:

[zpasswd]
recipe = z3c.recipe.dev:script
eggs = zope.password
module = zope.password.zpasswd
method = main

This will generate a script zpasswd next time you run buildout.

When run, the script will ask you for all parameters needed to create a typical principal entry, including the encrypted password.

Use:

$ bin/zpasswd --help

to get a list of options.

Using

$ bin/zpasswd -c some/site.zcml

the script will try to lookup any password manager you defined and registered in your environment. This is lookup is not necessary if you go with the standard password managers defined in zope.password.

A typical zpasswd session might look like:

$ ./bin/zpasswd

Please choose an id for the principal.

Id: foo


Please choose a title for the principal.

Title: The Foo


Please choose a login for the principal.

Login: foo

Password manager:

 1. Plain Text
 2. MD5
 3. SMD5
 4. SHA1
 5. SSHA
 6. BCRYPT

Password Manager Number [6]:
BCRYPT password manager selected


Please provide a password for the principal.

Password:
Verify password:

Please provide an optional description for the principal.

Description: The main foo

============================================
Principal information for inclusion in ZCML:

  <principal
    id="foo"
    title="The Foo"
    login="foo"
    password="{BCRYPT}$2b$12$ez4eHl6W1PfAWix5bPIbe.drdnyqjpuT1Cp0N.xcdxkAEbA7K6AHK"
    description="The main foo"
    password_manager="BCRYPT"
    />